Github: Forks, Collaborators, Watchers
Can apply to: Any project content stored on a Github instance, but primarily software and code
Metric definition: Github “Forks” are created when a user makes a copy of a repository (i.e., a group of files). A “collaborator” is another Github user who is able to perform many actions on the files within the repository, including edits. “Watchers” are Github users who have asked to be notified of activity in a repository, but have not become collaborators. Watching a repository is similar to following an RSS feed to see changes.
Metric calculation: Forks, pulls, and commits are counted by the Git software running on the Github servers.
Data sources: Github.com
Appropriate use cases: Forks, or copies, can indicate use or reuse of your repository, depending on the level of activity. For example, someone might fork your repository to suggest changes or as the basis for a new project. The identities of your Github collaborators may offer evidence of your engagement with particular communities, or possibly wide interest. Github watchers can indicate interest in your repository or project.
Limitations: Simple counts of forks, collaborators, and watchers do not provide much information about the use of the repository files. However, exploring the specific activities and individuals can provide contextual information about who is engaging with and reusing the content, as well as what kinds of activity. Not all Github users provide clear information about their role, affiliation, and identity.
Inappropriate use cases: Github metrics should not be used as a direct measure of quality or impact.
Transparency: All user actions for public repositories are publicly visible.
Timeframe: Real-time updates. The Github site was launched in April 2008.